moadoo



Febe 9, 1960 H. L. MCADOO DENTAL IMPRESSION TRAY Filed July 3. 1958 2Sheets-Sheet 1 Feb. 9, 1960 H, L, MCADOQ 2,924,011

DENTAL IMPRESSION TRAY Filed July 3. 195s 2 Sheets-Sheet 2 DENTALIMPRESSION TRAY Harold L. McAdoo, Bartlesville, Okla.

Application `luly 3, 1958, Serial No. 746,357

11 Claims. (Cl. 32-17) vrlhis invention relates to dental apparatus andparticularly to impression trays. In the making of f ull dentures,casts, impressions or prints of the upper jaw, the

with far less inconvenience to the patient so that a good impression maybe obtained the very first time. In addition, the resulting impressionobtained by the use of this invention is less likely to have flaws thanis true with impressions made by conventional means.

' This invention further provides a non-metallic type of tray which willhold impression materials whose ingredients are conducive to propercombination to create more effective molds. With this tray it has beendiscovered that it is possible to control dimensional changes andincrease fiexibility which will prevent dimensional distortion.

A further embodiment of this invention consists in the provision of atray made of fibrous material such as pressed wood-pulp, with edgeportions having less stock therein than the remaining portions of thetrays whereby to constitute a thin, moldable edge portion for forming agood seal when pressed against the roof and like portions of the mouthof a patient.

A preferred form of this invention consists of a fibrous dental trayproperly shaped to hold impression forming compound for oral prostheticwork, comprising a tray preformed of fibrous material, the fibrousmaterial being wood-pulp with a hardened outer surface, as for example avarnish covered surface, varnish being a suitable means to harden theouter surface thereof.

A still further object of this invention is to provide a wood-pulpdental tray which can be inserted, if so desired, in a less extensivemetallic tray, the wood-pulp tray holding the impression material andproviding soft fibrous edge portions for coming in contact with thepatients mouth.

A still further object of this invention is to provide both upper andlower type trays, singularly without an anterior handle, composed ofwoodpulp material adapted to be nested together in storage, and fortemporary employment, to be thrown away after once using and to bereplaced by another new or fresh one the'next time a tray is needed tohold impression material.

A still further object of this invention is to provide both upper andlower type dental trays composed of wood-pulp material adapted to bethrown away after once using,`each tray embodying means vforinter-connecting said tray with a permanent metal handle portion and ametal pressure plate, in

strong and rigid manner.

adetachable but otherwise Piice A still further object of this inventionis to provide an improved dental tray for holding moldable impressionmaterial until it is set, the tray formed of wood-pulp pressed todesired configuration, the wood-pulp normally soft and peelable, thetray coated with a film of varnish to give a relatively hard surfacewhen dry, and said tray capable of being softened by water and peeledfrom the impression material allowed to harden therein.

A still further object of this invention is to provide a dental traycomprising three parts or sections, two parts of which are metallic orotherwise rigid and durable, forming a permanent holder or support, andplace, while the other section, which is thin, may be composed4 ofpreformed, strong and tough wood-pulp, or substantially non -rigidmaterial coated with varnish, or other harden,- ing material; said trayadapted to be assembled with the two-part permanent sections, and is fortemporary employment, to be thrown away after once using and to bereplaced by another new or fresh one the next time a tray is to be usedto make an impression.

A still further object of this invention is to provide a dental trayformed of wood-pulp for assembly with a. metal handle and metal pressureplate, impression material to be held thereby when an impression istaken and a mold is poured therein and allowed to set. After theimpression and mold have set, or hardened, the tray with impression andmold are placed in water for a fewl minutes to soften the tray, whichcan then be peeled off from the impression material and discardedleaving a perfect impression cast and mold therein, from whichimpression cast the mold can then easily be removed.

A still further object of this invention is to provide a dental tray ofwood-pulp for assembly with a metal pres'-4 sure plate and metal handlemade of metal, such as stainless steel, the metal plate giving addedstrength tothe wood-pulp tray.

It has heretofore been the practice in making imprese sions of theupper, or lower jaw and the like, to select one rigid tray from fifty ormore dental trays which will fit the mouth of the patient and make agood seal against the roof of the mouth or other portions of the mouth.The tray must be thoroughly cleaned, filled with impression material andinserted into the mouth of the patient. If the tray employed in the artof dentistryA is -open at the back or lightly arched and does not make agood seal because its side portions are too high, the

` impression material displaced by the jaw will freely flow patientandto cause irritations.

' the storage of a large number of rigid trays of all shapes and sizes,all of which must be kept clean and the proout at the back. If a cast ofthe upper jaw is taken while the patient occupies a recumbent position,the ex.

cess material is liable to penetrate into the throat of the Thispractice requires curement of same and upkeep of which is veryexpensive. Applicant provides a novel, substantially rigid tray withthin terminal portions which will hold the impression maconstructed ofwood pulp, or other similar or suitable material, and produced at asmall cost, can be employed by the dentist as a single use tray, thetray to be thrown away after once using and to be replaced by anothernewL or fresh one for each impression.

Another object thereof is to provide a simple, efficient and inexpensivedental impression tray.

, Further objects of my invention will appear from;v the followingdescription thereof, taken in connection.

with the' attached drawings illustrating a preferred form of embodimentthereof, and in which: vl V Figure 1 is a partial section incombination'lwith ment "of a human head, having an upper dental tray em;

bodying the present invention within the mouth thereof, theV lower jawshown dotted, and illustrating the tray in section and iilled withimpression compound;

`Figure 2 is a partial section in combination with a fragment of4 thelewer jaw of a human head, having a lower dental tray embodying thepresent invention appliedv thereto, and illustrating the trayl insection and filled' with impression compound;`

Figure 3 is an upper-plan view of an upper, or maxillary type, wood pulpdental tray embodying the present invention;

Figure 4 is a. cross-sectional view of the wood-pulp trayf takensubstantially on line- 4'4 of Fig. 3, with a metal pressure plateassembled' therewith;

Figure 5i is a bttom plan view of the upper-'typer dental tray as shownby Figures 3l and 4, the pressure plate shown dotted in assembledposition;

Figure 6 is a longitudinal sectional Viewy taken substantially on line-6 6 of Fig. 5, the pressure. plate omitted;

Figure 7 is an exploded view showing the metal` handle andy metalpressure platein plan view as embodied in the invention;

Figure 8 is an exploded View showing the metal handle and metal pressureplate, shown by Figure 7, now in side elevation;

Figure 9 isa topA plan viewf of a lower, or mandibular type dental trayembodying the present invention, the pressure plate assembled therewith;

Figure l is a bottom plan View of the dental tray shown in Figure 9;

Figure ll. is av sectionall viewof-'the dental tray shown iii-Fig. 9,taken on line11-11 of Fig. 9; and

Figure 112 isa fragmentary sectional view taken substantially on line12-12 of Fig. 9.

Referring now to the drawings for a more particular description, 20indicates an upper, or maxillary type, wood pulp dental trayy providedwith a shape which closely: conforms to the roof 21 of the pati'entsmouth. The tray comprises a ridge portion 22v havingl a vault portion 23and a llange portion 24. Itwill be noted that flange portion 24.v variesfrom a minimum height at the heel H of the tray to a maximum at labialportion 25 as seen in Figures l and 6. The tray shown in Figures 1, 3,4, and 6 maybe supported by the dentistfs ngers, or preferably by arigid metal handle member.

A lower or-mandibular type dental tray 28 is indicated in Figures 2, 9,10, 11 and 12, said tray shaped with thin edge portions 31 to t thesurface of the lower jaw 29. It: is understood that in Figures 1 and 2there is indicated at 30 a comparativelyV thick layer of impressioncompound which is shown thick solely for convenience of illustration.V

The. trays 2G and 2S in the practice of the presentv invention are`formed of wood pulp for use with a compoundl having the characteristicof being adapted to ad here to the tray to which it is applied aftersolidilleation, and` thefurther characteristic of not adheringpermanently to. the-mouth of the patient.

The upper, or maxillary type, dental tray shown in Figures 1, 3, 4, 5.and 6 comprises a wood pulp tray for? temporary use properly shaped tohold impression com pound, the edge portions 32 being formed of lessthickness. for forming a good seal when pressed against the roof or likeportions of the mouth 4of a patient.

The mandibular type dental tray shown by- Figures 2.19.1. 1.0, 1,1 and12A is also constructed in the same manner and of like material as.described above. ber understood that the mandibular type dentaly traywill have the same thin, moldable edges and maybe fitted toa` lower jawwith equal facility ,and by" substantially the Same. method and means asthat herein described Afor the upper jaw.

The wood pulp trays-With varnished coated surface 33 eciently' hold theimpression compound and' can.

Itwill be used by a dentist, with or without the metal handle 34, ormetal pressure plate 35, shown by Figures 7 and 8.

When the wood pulp trays are desired to be used with the metal handle 34and metal plate 35, an aperture 36 is formed in the ridge portion 22 ofthe upper type tray 2.0, and an aperture 37 is formed in the ridgeportion 38 of the lower type tray 28. The pulp trays being Without thehandle portions Will nest with greater ease and require less space thanformer types with integral handle members.

The metal handle 34 clearly shown in Figures l, 2, 7 and 8 is formedwith a rear end portion 40, a body portionv 41, a pin-shaped forward endmale member 42, and ear portions- 43,` said ear portions 43 inclinedslightly downwardly from a horizontal plane extending through thehandle.

The metal pressure plate 35 is of horse-shoe shape with end portions 45and 46, an intermediate front portion 47 and a depending cylindrical pin48 with a lateral bore 50;

Said metal handle and pressure plate are designed. to be assembledtogether, the projecting male portion` 42 ofthe handlel adapted to tsnugly within the bore 50ct the pin 48- formed upon the lower surface ofplate 35. Said handle 34 and plate 35 will tit either the upper or lowertray when assembled therewith.

When said handle 34 and plate 35 assembled with the trayv 20 as shown byFig. 1, the compound 30 when applied, flows into the tray and on top ofthe plate 35. The dentist willt the tray -to the patients mouth bytrimmingA the edges 32 where necessary. The upward pressure applied bythe dentistto the handle 41 eects upward' pressure to the plate 35through the intermediation of male member 42 in bore 50 of pin 48.' Theears 43 will press upon the lower wall of the ridge portion 22 of tray20. Angular pressures can be exerted upon the handle and thus eiectangular relation movement of the tray-20 with the roof of the mouth ofthe patient.

After an impression is taken, the mold is poured therein; thereafter themold and the tray 20 are immersed in water to soften the tray. Thehandle 41 can be removed; however, the pressure plate remains betweenthe forward portion of tray 20 and` the rigid, set compound 30. Thelentire unit-tray,y mold, compound and tray are then removed from thewater at which time the tray can he peeled' from the model impressionand discarded. There is never any breakage of teeth on the mold ashappens when using metal trays and in prying the mold, or model,therefrom.

When the handle 34 and plate 35 are assembled with the lower type tray28, as shown by Fig. 3, the compound 30 when placed in the tray willcover the plate 35. The dentist will trim the edge portions of theftray28 and use similar techniques as described above with plate20.

I t is seen that theY time element is an important factor. The wood:pulp, trays,y can be made in numerous`r sizes fromlwhich, the dentistcan, choose. The dentist can trim thev trayA to individual mouth sizesvin less time than he would-spend in waxing; up a, metal, or 4hardmaterial tray, only to nd out he must use a dierent size tray; Thetrimmed wood pulptrays are. less damaging to the mouthl as they do notcut or harm the tender tissues thereof. These trays are made of pressedwood pulp and coated with varnish 33, or some other satisfactoryprotecti've coatingl which allowsy the tray to soften in water and bepeeled from the model impression, and mold.

The quick; removable handle 34' and inner support plate 35 can be madefrom any hard metal, the metal illustrated being` stainless steel'. Theycan be used on any` upper tray if the, upper tray used is provided withaperture 36, and. with a lower tray if provided with an aperture 37 toreceive. the. pin 48. The combined handle and pressure plate gives addedstrength to; the; woodA pulp tray and 'are efficiently interchangeablewith either upper or lower trays.

It will be understood that the construction shown in the various figuresof the drawing, and above described, pertains to a novel invention whichis equally useful in connection with the making of full dentures, casts,impressions or prints of the upper jaw, the lower jaw, or for making ofdental prosthetics, such as bridges and partial plates.

The types of trays shown and described are preferably wood pulp dentaltrays which will hold impression materials to create effective molds.The thin extremities of the trays are intended to reduce the mouthirritation when said outer extremities of the tray are pressed againstthe mouth portions of the patient. The sanitary feature is veryimportant as the tray is made at a small cost and is for temporaryemployment, -to be thrown away after once using and to be replaced byanother new or fresh one the next time a tray is needed lto holdimpression material.

It may be desirable to make the wood pulp tray in various sizes.However, it is estimated that a maximum of ten different sizes of upperand lower type trays which can be cut or trimmed to size will replaceapproximately seventy different sizes of metallic trays as now employedin the dental profession. The fibrous, or wood pulp, trays will beconstructed so that they can be cut, or trimmed, at the peripheraledges, and especially at the heel of the lower type trays, andespecially the thin heel of the central portion of the tray which comesin contact with the palate, or roof portion, of the patients mouth.

A substantial advantage accruing from the use of the present invention,will become manifest in connection with the manufacture of plaster ofParis casts from the impression. As is well known, an impression ofcornpound in a tray is first formed and thereafter a plaster i of Pariscast of this impression must be made. After the plaster of Paris hasset, it is necessary to separate the plaster of Paris cast from thecompound and tray. By virtue of the present invention, it is muchsimpler to remove the wood pulp tray by peeling it from the impressionmaterial, and/or the plaster of Paris cast, in place of removing theplaster of Paris cast from a rigid metal tray. Hence the sanitaryfibrous tray shown and described is a great improvement over the priorart.

Having thus described my invention, what I claim as new therein anddesire to secure by Letters Patent is:

l. An improved preformed dental tray for holding moldable impressionmaterial until set, said tray formed of wood pulp pressed to its desiredconfiguration, said wood pulp normally relatively soft and peelable,saidpre formed tray covered with a thin film of liquid Y,varnish whichelects a relatively hard surface thereto when dry, and said tray capableof being softened by water and peeled from the impression materialallowed to harden therein.

2. An improved dental tray according to claim 1 including a rigidpressure plate and a rigid removable handle assembled therewith.

3. An improved dental tray according to claiml ineluding a metalpressure plate and a metal removable handle assembled therewith.

4. A dental tray properly shaped to hold impression forming compound fororal prosthetic work, comprising a thin preformed wood pulp tray, apressure plate and a removable handle, said wood pulp tray forming adental tray with a thick central ridge and thin flange portion, saidconstruction providing a tray with peripheral edge portions havnig lessstock ltherein than the remaining portions of the tray, constituting athin, moldable edge portion for forming a good seal when pressed againstthe roof and like portions of the mouth of a patient, and said removablehandle for said tray prgvided with an extend ing male member forslidably mounting with the pressure plate in said tray.

5. A dental tray with removable parts properly shaped to hold impressionforming compound for oral prosthetic work, comprising a tray wo'od pulpmaterial, a removable metal hadnle and a metal plate, said tray having acentral portion, ridge and flange portions, said construction providinga tray with peripheral edge portions having less stock therein than theremaining portions of the tray constituting a thin, relatively soft,moldable edge portion for forming a good seal when pressed against theroof and like'portions of the mouth of a patient, said removable handleembodying a male member for slidably mounting with a female memberintegrally formed with said metal plate assembled with said tray.

6. A wood pulp dental tray with removable handle and pressure plate fortaking lower or mandibular impressions, said tray comprising ridge andlabial portions, said labial portions extending outwardly at an angle tosaid ridge portion and having less stock in its peripheral edge portionsthan the remaining portions of the tray forming a feather edge rimwhereby to constitute a ridge portion of stiffness and rigiditysurrounded by an outer less rigid labial peripheral edge portion, saidhandle made of rigid metal with a male member at one end thereof, saidpressure plate having a depending portion with a female portion therein,said male member for slidably mounting with said female portion whensupporting said tray, said tray capable of being softened by water andpeeled from the impressions formed in said tray.

7. In a dental spoon with a removable handle and pressure plate fortaking impressions of the upper jaw, in combination, a preformed woodpulp spoon, said spoon rounded at the back, has divergent edges and arimmed concave front, a rear portion concave in cross section in respectto its central portion, said portions meeting at a feather edge rim, aremovable metal handle with a male member extending forwardly from saidtray, and pin means attached to the intermediate portion of a horse-shoeshaped plate and depending therefrom, said pin means extending throughsaid tray when assembled therewith, said male member engaging said pinwhen said handle is assembled with said tray and said plate, said traycapable of being softened by water and peeled from any impressions madeand formed in said tray.

8. A dental tray properly shaped to hold impression forming compound fororal prosthetic work, comprising a preferred tray of wood pulp material,a metal handle and a metal plate, said wood pulp tray embodying a thickwood pulp central portion, a thick wood pulp ridge portion, and a thinwood pulp flange portion, said construction providing a tray withperipheral edge poritons having less stock therein than the remainingportions of the tray constittuing a thin, soft, moldable edge portionfor forming a good seal when pressed against the roof and like portionsof the mouth of a patient, said metal handle forming a removable handlefor said tray, said metal handle provided at one end thereof with a maleextending portion for slidably mounting with female means secured to themetal plate assembled with and arranged inside said tray.

9. An improved preformed dental tray to hold moldable impressionmaterial until set, said tray formed of wood pulp normally relativelysoft and coated with a thin and uniform hn of varnish elfecitng arelatively hard surface thereto, and said tray capable of being softenedby water and peeled from the impression material allowed to hardentherein.

l0. An improved preformed dental tray to hold impression material, saidtray formed of wood pulp pressed to a desired configuration and coatedwith a relatively hard surface film, said tray capable of being softenedby water and peeled from impression material allowed to harden therein,said tray including a metal pressure plate of curved configuration andhaving free end portions, a

.metal pin integrally formed with said plate and depend jacent wall ofthe tray assembled therewith.

11. An .improved preformed dental tray to :hold .im pression material,said tray formed of Wood pulp pressed to a desired configuration andcoated with a relatively hard surface film, said tray capable of beingsoftened by water and peeled from impression materiaI allowed to Iharden therein, said tray vincluding a metal pressure plate 48 ofhorse-shoe configuration and a metal pin integrally 'formed therewithand depending from the curved 4portion intermediate its free ends, said:tray having an aperture "therethrough to receive said pin, Vsaid pinhaving a transyerse bore `therein, a metal handle embodying means for'assembly with the depending portion of said pin to sup- .p'ort saidtray and eiect pressure to said plate, said handle means for supportingthe tray being a male member 'projecting from one free end thereof, andsaid handle having ear portions for contacting said tray when said malemember is assembled Within the bore of said pin.

. .References Cited in the le of this :patent UNITED STATES PATENTS'S'QSO Block May 22, 1900 1,503,580 Epstein Aug. 5y, 1924 2,241,013

Coble June 24, 11941 www.

